The aptitude to render graphics on high of different working purposes on the Android working system permits distinctive person interface enhancements and functionalities. For instance, a person may make use of this performance to create a floating widget displaying system info whereas concurrently utilizing an internet browser or different utility. That is completed via system-level permissions and cautious administration of the window layer.
This function supplies builders with the power to supply overlays for varied functions, from bettering accessibility to rising productiveness. Traditionally, the power to show visible components on high of different purposes was reserved for system-level processes. Nevertheless, fashionable Android variations grant particular permissions that enable third-party purposes to leverage this performance, supplied customers explicitly grant the required permission. This contributes to a extra customizable and interactive person expertise, significantly in multitasking situations.
The next sections will delve into the technical points concerned in implementing this functionality, together with the required permissions, implementation approaches, and concerns for person expertise and safety.
1. System Alert Window
The “System Alert Window” permission represents a basic part of the Android working system’s overlay performance, appearing because the linchpin for purposes in search of the aptitude to render visible components on high of different working processes. With out this permission, purposes can not execute the core perform of graphical overlay, rendering it inconceivable to attain the specified ‘drawing over different apps’ conduct.
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Permission Granting and Revocation
Consumer consent is paramount. The Android system mandates specific person approval earlier than an utility can purchase the “System Alert Window” permission. This includes navigating to system settings and granting the permission. Customers retain the appropriate to revoke this permission at any time, successfully disabling the applying’s means to attract overlays. This mechanism supplies an important layer of management and safety, stopping unauthorized visible interference.
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Window Sort Specification
The “System Alert Window” permission permits the creation of home windows with a particular kind that determines their placement throughout the window layering hierarchy. These window sorts dictate whether or not the overlay will seem above standing bars, enter strategies, or different purposes. Deciding on the suitable window kind is essential to make sure the overlay capabilities as supposed with out obstructing important system components. Incorrect window kind choice might result in undesired visible conflicts or stop the overlay from being seen in any respect.
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Z-Order and Visibility
The relative stacking order (Z-order) of those home windows is managed by the system, with newer overlays sometimes showing on high. Nevertheless, purposes can programmatically affect their Z-order to some extent. Environment friendly administration of Z-order is essential for stopping unintentional obscuration of different utility components and guaranteeing the overlay stays seen and aware of person interplay. Poor Z-order administration can result in a degraded person expertise, significantly when a number of purposes try to attract overlays concurrently.
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Safety Implications
The ability to attract over different purposes introduces potential safety vulnerabilities. Malicious purposes might exploit this permission to create pretend system dialogs, seize delicate person enter, or conduct phishing assaults. Due to this fact, Android imposes strict limitations and pointers on the usage of “System Alert Window”. Builders are liable for guaranteeing their overlays are clear, clearly identifiable, and don’t mimic system UI components. Failure to stick to those pointers can lead to utility rejection or removing from the Google Play Retailer.
In abstract, the “System Alert Window” permission acts as a essential gateway, regulating entry to the performance permitting purposes to attract visible components over different working processes. The permission’s granting, window kind specification, Z-order administration, and inherent safety implications underscore the complexity and potential threat related to this performance, highlighting the necessity for accountable implementation and stringent person management.
2. Overlay Permission
The “Overlay Permission” serves because the foundational requirement for any Android utility aiming to implement the performance of displaying visible components on high of different concurrently working purposes. Its existence represents a binary situation; with out this permission, an utility is basically incapable of “drawing over different apps android.” The connection is causal: the granting of the permission is a obligatory antecedent for the performance to develop into operational. Take into account, for instance, a floating calculator utility. Its means to look superimposed on different purposes, resembling an internet browser or a doc editor, hinges fully on the person having explicitly granted the requisite overlay permission. The dearth of this permission would render the calculator confined to standard utility conduct, unable to manifest as a persistent overlay.
Moreover, the sensible significance of understanding this relationship extends to improvement workflows and person expertise concerns. Builders should meticulously deal with situations the place the person has not granted the overlay permission, implementing swish degradation or clear prompts guiding the person towards granting the required entry. A typical observe includes displaying an informative dialog explaining the aim of the permission and offering a direct hyperlink to the system settings the place the permission might be enabled. This method promotes transparency and enhances person belief. One other use-case is in customized system launchers, which make the most of the overlay permission to show fast entry menus and widgets on high of the person’s at the moment lively utility. Once more, the correct dealing with of conditions the place the overlay permission has not been granted is crucial for a optimistic person expertise.
In conclusion, the overlay permission is an indispensable part of implementing the aptitude to render graphics above different working purposes on the Android platform. Its presence determines the feasibility of the performance, and its correct dealing with straight impacts each the person expertise and the safety concerns surrounding purposes that make the most of this highly effective function. Builders should acknowledge the criticality of this permission and implement sturdy mechanisms to deal with situations the place it’s both granted or denied, fostering a safe and user-friendly setting.
3. WindowManager Management
WindowManager Management is a pivotal facet of implementing the aptitude to render visible components on high of different purposes throughout the Android setting. This management mechanism supplies the interface via which an utility manipulates the window layering system, figuring out the visibility, place, and conduct of overlay components. The “drawing over different apps” performance depends closely on the power so as to add, replace, and take away home windows from the WindowManager, successfully orchestrating the looks and interactivity of the overlay. An instance of that is seen in display recording purposes, the place the overlay displaying recording controls is managed through WindowManager, permitting it to stay seen whatever the utility at the moment in focus.
The WindowManager.LayoutParams class performs an important function in defining the traits of an overlay window. Parameters resembling window kind (e.g., TYPE_APPLICATION_OVERLAY, TYPE_SYSTEM_ALERT), flags (e.g., FLAG_NOT_FOCUSABLE, FLAG_NOT_TOUCH_MODAL), and pixel format are configured via this class. For example, setting the FLAG_NOT_FOCUSABLE permits the overlay to obtain contact occasions with out stealing focus from the underlying utility. Equally, the window kind dictates the layer wherein the overlay is positioned, impacting its visibility relative to different system components. The right configuration of those parameters is crucial to attain the specified visible impact and interplay mannequin of the overlay. A sensible utility of this may be present in accessibility instruments, the place overlays present real-time textual content translation or display magnification. Such overlays should be fastidiously managed via WindowManager to make sure they’re each seen and non-intrusive.
In conclusion, WindowManager Management constitutes an indispensable part within the implementation of “drawing over different apps”. It supplies the means to create, configure, and handle overlay home windows, dictating their look, conduct, and interplay with the underlying system. Whereas highly effective, efficient utilization of WindowManager requires a deep understanding of its parameters and their implications, in addition to adherence to greatest practices to make sure stability, safety, and a optimistic person expertise. Challenges exist in coordinating a number of overlays and stopping conflicts with system UI components, highlighting the necessity for cautious planning and testing throughout improvement.
4. Canvas Manipulation
Canvas Manipulation varieties a essential technical layer within the implementation of visible overlays on the Android platform. This method facilitates direct pixel-level management, enabling builders to render customized graphics, animations, and textual content components on high of different purposes. The performance to “draw over different apps android” hinges on the power to control the canvas object, which serves because the drawing floor for the overlay window.
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Drawing Customized UI Components
Canvas manipulation supplies the power to create bespoke person interface components that aren’t available via customary Android UI elements. For example, a system monitoring software may render a real-time graph of CPU utilization as an overlay. This requires drawing traces, shapes, and textual content dynamically onto the canvas, responding to adjustments in system information. This degree of customization can be unattainable with out direct canvas manipulation. Equally, drawing signatures or annotations on screenshots displayed as overlays necessitates exact management over pixel placement on the canvas.
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Implementing Animations and Transitions
Animations and transitions considerably improve the person expertise of overlays. Canvas manipulation permits for the creation of advanced animations by iteratively redrawing the canvas with barely modified parameters. A loading indicator overlay, for instance, might use canvas rotation and shade changes to create a visually interesting animation. Furthermore, transitions between totally different overlay states (e.g., increasing a minimized widget) might be applied by steadily modifying the canvas content material over time, offering a clean and fascinating visible expertise.
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Dynamic Textual content Rendering
The flexibility to render textual content dynamically on the canvas is crucial for displaying info and offering directions inside an overlay. Canvas manipulation permits builders to regulate the font, dimension, shade, and placement of textual content with pixel-level accuracy. That is significantly helpful for displaying real-time information, resembling inventory costs or sports activities scores, on high of different purposes. Moreover, dynamic textual content rendering can be utilized to supply contextual assist or steering to customers throughout the overlay, adapting the displayed textual content based mostly on the present state of the applying.
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Picture Compositing and Filtering
Canvas manipulation permits the compositing of a number of photos and the applying of assorted filters to create advanced visible results. An utility may overlay a semi-transparent watermark onto the display to discourage unauthorized display recording. This includes loading the watermark picture, setting its transparency, and drawing it onto the canvas in a particular location. Moreover, canvas manipulation can be utilized to use picture filters, resembling blurring or shade changes, to boost the visible attraction of the overlay or to create particular results, like highlighting sure areas of the display.
These points of Canvas Manipulation are indispensable for purposes in search of to successfully draw over different apps on Android. From creating customized UI components and implementing animations to rendering dynamic textual content and compositing photos, canvas manipulation supplies the flexibleness and management essential to ship compelling and informative overlay experiences. The accountable and environment friendly use of those methods is essential for guaranteeing a optimistic person expertise and minimizing efficiency affect on underlying purposes.
5. Contact Occasion Dealing with
The flexibility to intercept and course of person contact enter is intrinsically linked to the performance of “drawing over different apps android.” With out sturdy contact occasion dealing with, an overlay would exist merely as a passive visible component, missing interactivity and considerably diminishing its utility. The overlay, in essence, turns into non-functional if it can not reply to person enter. The cause-and-effect relationship is direct: person contact occasions set off the execution of predefined actions throughout the overlay utility, enabling the overlay to perform as an interactive interface. For instance, a floating video participant, rendering on high of different purposes, requires contact occasion dealing with to handle playback controls (play, pause, quantity adjustment) straight on the overlay window. The absence of this functionality would necessitate switching again to the video participant’s foremost utility window for management, defeating the aim of the overlay.
Efficient contact occasion dealing with in overlays calls for cautious consideration of occasion propagation and coordination with the underlying utility. Relying on the supposed conduct, the overlay might both devour the contact occasion, stopping it from reaching the applying beneath, or cross the occasion via. This selection has substantial implications for the person expertise. For example, a drawing utility applied as an overlay should devour contact occasions to permit the person to attract straight on the display. Conversely, a notification show overlay may enable contact occasions to cross via to the underlying utility until the person interacts with the notification itself. Libraries like “GestureDetector” and cautious implementation of “onTouchEvent” are generally employed to handle varied contact gestures (single faucet, double faucet, swipe) and their corresponding actions. The sensible significance of understanding the refined interaction between occasion dealing with, visible presentation, and utility coordination is paramount in delivering a seamless and intuitive person expertise.
In abstract, contact occasion dealing with varieties an indispensable part of any utility in search of to implement the “drawing over different apps” functionality. It governs the interactivity of the overlay, dictates its responsiveness to person enter, and determines its general usability. Challenges usually come up in managing contact occasion conflicts between the overlay and the underlying utility, requiring cautious design and implementation to make sure each purposes perform harmoniously. The flexibility to deal with contact occasions successfully will not be merely a technical requirement however fairly a basic determinant of the overlay’s worth and its means to combine seamlessly with the Android ecosystem.
6. Z-Order Administration
Z-Order Administration performs a essential function within the implementation of purposes designed to render graphics on high of different working purposes on the Android platform. It governs the visible hierarchy of overlapping home windows, figuring out which components seem within the foreground and that are obscured. The performance of “drawing over different apps android” is straight depending on efficient Z-Order Administration to make sure overlays are seen and interactable as supposed.
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Window Layering Hierarchy
The Android system employs a layered windowing system the place every window is assigned a Z-order, dictating its place relative to different home windows. Overlays, applied to “draw over different apps android,” should be positioned inside an applicable layer to make sure visibility above the goal utility. Window sorts, resembling `TYPE_APPLICATION_OVERLAY` and `TYPE_SYSTEM_ALERT`, affect this placement. For instance, a floating widget displaying system info must reside in a better layer than the applying it overlays to stay seen. Incorrect layering can lead to the overlay being obscured, rendering it non-functional.
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Managing Overlapping Overlays
In situations the place a number of purposes try to “draw over different apps android” concurrently, Z-Order Administration turns into significantly advanced. The system should resolve conflicts to find out the stacking order of those overlays. Purposes can affect their Z-order to some extent, however the system retains final management. This may result in surprising conduct if a number of overlays compete for a similar display area. For example, two floating purposes displaying notifications may obscure one another until their Z-order is fastidiously managed, doubtlessly requiring dynamic adjustment based mostly on person interplay or precedence.
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Affect on Consumer Interplay
The Z-order straight impacts how customers work together with overlays and underlying purposes. An overlay designed to seize contact occasions should be positioned appropriately within the Z-order to obtain these occasions. If the overlay is positioned behind one other window, it won’t obtain contact enter, rendering it unusable. Equally, if an overlay unintentionally obscures essential components of the underlying utility, it might probably hinder usability. Take into account a display recording utility; the overlay displaying recording controls should be positioned in a fashion that doesn’t hinder important components of the applying being recorded.
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System Window Administration Issues
System-level home windows, such because the standing bar and navigation bar, additionally take part within the Z-order hierarchy. Purposes that “draw over different apps android” should contemplate these system components to make sure their overlays don’t battle with them. Overlays that inappropriately obscure system UI components can result in a degraded person expertise and potential system instability. For instance, an overlay that utterly covers the standing bar may stop customers from accessing system notifications, requiring cautious consideration of window flags and Z-order placement to keep away from such conflicts.
In abstract, efficient Z-Order Administration is essential for purposes that “draw over different apps android”. The layering of home windows, the dealing with of overlapping overlays, and the affect on person interplay are all straight ruled by how the Z-order is managed. Poor Z-Order Administration can result in usability points, system instability, and a unfavorable person expertise, highlighting the significance of cautious planning and implementation.
7. Useful resource Optimization
Purposes able to rendering graphics atop different purposes within the Android setting are inherently topic to stringent efficiency calls for. The exercise of “drawing over different apps android” introduces a further computational load, doubtlessly impacting the responsiveness and battery lifetime of the system. Useful resource optimization, subsequently, turns into an indispensable part. The introduction of an overlay, if poorly optimized, can demonstrably degrade the efficiency of the underlying utility. A poorly optimized floating video participant, as an example, might devour extreme CPU cycles, resulting in dropped frames and stuttering playback, even throughout the underlying utility.
Sensible useful resource optimization methods embody varied methods. Limiting the frequency of redraws is paramount; overlays ought to solely be up to date when obligatory, fairly than repeatedly refreshing the canvas. Using environment friendly drawing methods, resembling using {hardware} acceleration the place attainable and minimizing the usage of alpha mixing, can considerably cut back the processing overhead. Moreover, cautious administration of bitmap sources, avoiding pointless allocations and aggressively recycling bitmaps when they’re not wanted, contributes to decreased reminiscence consumption. For example, an accessibility software that gives real-time display magnification as an overlay should implement these optimization methods to keep away from sluggish efficiency and guarantee a clean person expertise.
In conclusion, the seamless integration of overlays into the Android ecosystem necessitates a robust emphasis on useful resource optimization. The efficiency affect of “drawing over different apps android” might be vital, however via cautious coding practices and the applying of optimization methods, builders can mitigate these results and ship overlays which might be each visually interesting and performant. This requires a proactive method, incorporating useful resource optimization concerns all through the event lifecycle to make sure a optimistic and environment friendly person expertise. The objective is to attenuate the efficiency affect on the system, permitting it to supply a high-quality person expertise with out pointless efficiency drains or battery consumption points.
8. Safety Issues
The flexibility for an utility to render visible components over different working purposes presents inherent safety dangers throughout the Android working system. This functionality, whereas enabling legit functionalities, additionally opens avenues for malicious actors to take advantage of person belief and doubtlessly compromise system integrity.
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Overlay Assaults
Overlay assaults characterize a big menace. Malicious purposes can create pretend system dialogs that mimic legit prompts, tricking customers into granting delicate permissions or divulging confidential info. For example, a pretend “System Replace” dialog displayed over a banking utility might request the person’s credentials. The unsuspecting person, believing the immediate originates from the system, might inadvertently expose their banking particulars. The “drawing over different apps android” function, when abused on this method, permits the malicious overlay to convincingly masquerade as a trusted system part, resulting in potential information breaches.
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Clickjacking
Clickjacking includes concealing malicious actions beneath seemingly innocuous UI components. A clear overlay positioned over legit buttons or hyperlinks can redirect person enter to unintended locations. A person aspiring to click on a “Like” button on a social media utility may unknowingly set off a cost authorization on the overlay. The flexibility to “draw over different apps android” is exploited to create this misleading layer, manipulating person interplay with out their consciousness. The sort of assault can lead to unauthorized fees, information theft, or the set up of malware.
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Information Exfiltration
Malicious overlays can seize delicate info displayed on the display, resembling passwords, bank card numbers, or private messages. By repeatedly monitoring the display content material and transmitting the captured information to a distant server, attackers can exfiltrate confidential info with out person consent. The “drawing over different apps android” functionality supplies the mechanism for the overlay to stay persistently lively and monitor display content material, turning it right into a silent surveillance software. The sort of assault is especially harmful because it operates within the background, usually undetected by the person till vital injury has been carried out.
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Permission Abuse
Even seemingly benign purposes with the “draw over different apps android” permission can pose a threat. Over time, builders may introduce malicious code into beforehand trusted purposes via updates. Alternatively, vulnerabilities within the utility’s code might be exploited by attackers to inject malicious overlays. In these situations, the initially granted permission turns into a gateway for unauthorized entry and malicious exercise. The beforehand legit utility transforms right into a Computer virus, utilizing its privileged place to carry out actions past its unique scope.
These safety concerns spotlight the inherent dangers related to granting the power to “draw over different apps android.” Whereas legit purposes make the most of this functionality for useful functions, the potential for abuse necessitates vigilance and the implementation of strong safety measures to guard customers from malicious overlays and their related threats.
Incessantly Requested Questions Relating to “Drawing Over Different Apps Android”
The next addresses frequent inquiries and misconceptions surrounding the performance of drawing visible components over different working purposes on the Android working system. It’s supposed to supply clear and concise info for builders and customers alike.
Query 1: What constitutes “drawing over different apps android”?
This refers back to the functionality of an Android utility to render visible components, resembling home windows, graphics, or textual content, on high of different concurrently working purposes. That is achieved via the usage of particular system permissions and the Android WindowManager API.
Query 2: What permissions are required to implement “drawing over different apps android”?
The first permission required is “SYSTEM_ALERT_WINDOW”. This permission should be explicitly granted by the person through system settings earlier than an utility can draw overlays. With out this permission, the performance won’t function.
Query 3: What are the potential safety dangers related to “drawing over different apps android”?
This performance might be exploited for malicious functions, together with overlay assaults, clickjacking, and information exfiltration. Attackers can create pretend system dialogs to trick customers into granting permissions or divulging delicate info. Customers ought to train warning when granting this permission.
Query 4: How does an utility handle contact occasions when “drawing over different apps android”?
Purposes should implement contact occasion dealing with mechanisms to reply to person enter on the overlay window. The applying can both devour the contact occasion or cross it via to the underlying utility, relying on the specified conduct.
Query 5: How can efficiency be optimized when “drawing over different apps android”?
Useful resource optimization is essential to attenuate the affect on system efficiency. This consists of limiting redraw frequency, using {hardware} acceleration, and effectively managing bitmap sources. Poorly optimized overlays can considerably degrade system responsiveness and battery life.
Query 6: How does the Android system handle Z-order when a number of purposes are “drawing over different apps android”?
The Android system employs a layered windowing system the place every window is assigned a Z-order, figuring out its visible precedence. System components, such because the standing bar, additionally take part within the Z-order hierarchy. Overlays should be appropriately layered to make sure visibility and keep away from conflicts.
In abstract, the power for an utility to render components over different apps presents each highly effective capabilities and inherent safety dangers. Customers should train warning when granting the SYSTEM_ALERT_WINDOW permission and builders should guarantee accountable and performant implementation.
The next part will discover greatest practices and pointers for implementing “drawing over different apps android” in a safe and user-friendly method.
Suggestions for Implementing “Drawing Over Different Apps Android” Responsibly
The next pointers present important suggestions for builders in search of to implement the “drawing over different apps android” performance whereas prioritizing person expertise, safety, and system stability.
Tip 1: Request the SYSTEM_ALERT_WINDOW Permission Judiciously: Implement a transparent and concise clarification to the person detailing the exact explanation why the overlay permission is critical for the applying’s performance. Keep away from obscure or deceptive justifications. A screen-dimming utility, for instance, ought to explicitly state that the permission permits it to cut back display brightness past the system’s default settings.
Tip 2: Reduce the Overlay Footprint: Design overlays to be as unobtrusive as attainable. Keep away from masking important UI components of the underlying utility. A floating notification widget, as an example, must be designed to be small, clear, and simply dismissible to attenuate disruption to the person’s workflow.
Tip 3: Implement Sturdy Contact Occasion Dealing with: Be certain that contact occasions are appropriately dealt with throughout the overlay window. Keep away from by accident intercepting contact occasions supposed for the underlying utility. If the overlay will not be supposed to be interactive, explicitly cross contact occasions via to the underlying utility to take care of performance.
Tip 4: Prioritize Useful resource Optimization: Reduce the computational overhead related to rendering the overlay. Make use of environment friendly drawing methods, restrict redraw frequency, and handle reminiscence sources fastidiously. Constantly monitor the applying’s efficiency to establish and handle potential bottlenecks that will affect system responsiveness.
Tip 5: Adhere to Materials Design Ideas: Keep visible consistency with the Android system by adhering to Materials Design ideas. Keep away from mimicking system UI components, resembling dialog bins or notifications, to stop person confusion and potential exploitation.
Tip 6: Repeatedly Monitor for Safety Vulnerabilities: Proactively handle potential safety vulnerabilities within the utility code. Keep knowledgeable about frequent overlay assault vectors and implement applicable safeguards to stop malicious exploitation. Repeatedly replace dependencies and libraries to patch recognized safety flaws.
Tip 7: Present an Straightforward Option to Disable the Overlay: Provide customers a simple mechanism to disable the overlay performance utterly. This supplies customers with management over the applying’s conduct and permits them to simply disable the overlay whether it is inflicting issues or conflicts.
The following tips emphasize the significance of accountable implementation when working with the “drawing over different apps android” function. By adhering to those pointers, builders can reduce dangers and ship a optimistic person expertise.
The ultimate part summarizes key takeaways and supplies a concluding perspective on the usage of this performance.
Conclusion
The previous sections have explored the technical and safety implications of “drawing over different apps android.” This performance, whereas providing distinctive capabilities for utility enhancement and customization, presents vital challenges associated to person expertise, system stability, and potential malicious exploitation. Implementing such options requires a complete understanding of the underlying Android windowing system, related permissions, and proactive mitigation of safety dangers.
The accountable utility of the “drawing over different apps android” function necessitates a dedication to transparency, person management, and sturdy safety practices. Builders should fastidiously weigh the advantages in opposition to the potential dangers and prioritize the person’s greatest pursuits. Continued vigilance and adherence to evolving safety pointers are essential to sustaining the integrity of the Android ecosystem and fostering person belief in purposes that make the most of this highly effective, but doubtlessly harmful, functionality.
